1) Field of the Invention
The present invention relates to a photosensitive resin composition and a photosensitive dry film containing the same, and in particular relates to a photosensitive resin composition from which an excellent development property as well as a resist pattern excellent in sand blast proof property are obtained when formed into the dry film.
2) Description of the Related Art
Conventionally, as a method for selectively engraving a material to be processed such as glass and ceramics, there has been known a method which is called a sand blast processing. In the sand blast processing, a patterned photosensitive resin layer is provided as a masking material on the material to be processed and subsequently an unmasked portion is selectively engraved by blasting an abrasive on this photosensitive resin layer. The sand blast processing has been utilized for formation of a rib (partition) which defines each cell in a plasma display, and pattern formation of a circuit substrate having both a metallic pattern and an insulating pattern of the ceramics and a phosphor.
A photosensitive dry film has been used for forming a masking material used for the sand blast processing. This photosensitive dry film is a film with three layer structure obtained by coating a photosensitive resin composition on a removable support film, half drying this coating film to form a photosensitive resin layer and laminating a removable protection film thereon. Upon the use thereof, the protection film is peeled off from the photosensitive resin layer, the uncovered photosensitive resin layer is overlaid on a material to be processed, and the photosensitive resin layer is press-bonded by adding the pressure via the support film. Subsequently, the resist pattern which is the masking material in the sand blast processing is formed by exposing the photosensitive resin layer to light through the support film, peeling the support film off, and subjecting the resin layer to a developing treatment.
In recent years, along with progress of photolithography and sand blast technique, rib formation with finer pattern has been desired in the plasma display.
Aiming at efficient production of such a fine rib pattern with a high process yield, there have been reported a variety of many photosensitive resin compositions containing a carboxy-modified urethane (meth)acrylate compound and a photopolymerization initiator. For example, Patent Document 1 (JP-H8-54734-A) discloses a photosensitive resin composition containing a carboxy-modified urethane (meth)acrylate with an acid value of 20 to 70 mg KOH/g, an alkali soluble polymer compound and a photopolymerization initiator.
Patent Document 2 (JP-H11-181042-A) discloses a photosensitive resin composition containing both a carboxyl group-containing acrylic urethane based resin having an acid value of 10 to 100 mg KOH/g and an acrylic urethane based resin having a certain segment moiety, in addition to a photopolymerization initiator.